21.—You have been on tour for a week in our city during May Day. What do you think about it?
—Oh, what __________ different Yancheng! It isn’t ___________ I saw last.
A. /, the one B. a, the one C. a, one D. /, one
22. The Chinese government has made it clear _______ it tries to achieve in space science in the next 5 years.
A. what B. that C. how D. which
